title: Elucidation of the mode of interaction in the UP1-telomerase RNA-telomeric DNA ternary complex which serves to recruit telomerase to telomeric DNA and to enhance the telomerase activity.
abstract: We found that UP1, a proteolytic product of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1), both enhances and represses the telomerase activity. The formation of the UP1-telomerase RNA-telomeric DNA ternary complex was revealed by a gel retardation experiment. The interactions in the ternary and binary complexes were elucidated by NMR. UP1 has two nucleic acid-binding domains, BD1 and BD2. In the UP1-telomerase RNA binary complex, both BD1 and BD2 interact with telomerase RNA. Interestingly, when telomeric DNA was added to the binary complex, telomeric DNA bound to BD1 in place of telomerase RNA. Thus, BD1 basically binds to telomeric DNA, while BD2 mainly binds to telomerase RNA, which resulted in the formation of the ternary complex. Here, UP1 bridges telomerase and telomeric DNA. It is supposed that UP1/hnRNP A1 serves to recruit telomerase to telomeric DNA through the formation of the ternary complex. A model has been proposed for how hnRNP A1/UP1 contributes to enhancement of the telomerase activity through recruitment and unfolding of the quadruplex of telomeric DNA.
authors.affiliation: Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Takada
authors.forename: Asami
authors.initials: A
authors.lastname: Ono
authors.forename: Kayoko
authors.initials: K
authors.lastname: Nagata
authors.forename: Yuki
authors.initials: Y
authors.lastname: Konishi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nukina
authors.forename: Manami
authors.initials: M
authors.lastname: Ono
authors.forename: Akimasa
authors.initials: A
authors.lastname: Matsugami
authors.forename: Ayako
authors.initials: A
authors.lastname: Furukawa
authors.forename: Natsuki
authors.initials: N
authors.lastname: Fujimoto
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Fukuda
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakagama
authors.forename: Masato
authors.initials: M
authors.lastname: Katahira
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D006367:HeLa Cells; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D019098:Telomerase / Q000737:chemistry* / Q000378:metabolism; D016615:Telomere / Q000737:chemistry*
chemical_list: D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; C000619656:hnRNPA1 protein, human; C422952:telomerase RNA; D012313:RNA; D004247:DNA; D019098:Telomerase